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Propagation equations for test bodies with spin and rotation in theories of gravity with torsion
We generalize the Papapetrou equations by deriving propagation equations for the energy-momentum and angular momentum of a test body which has both elementary-particle spin and macroscopic rotationExpand
On the determination of Cauchy surfaces from intrinsic properties
We consider the problem of determining from intrinsic properties whether or not a given spacelike surface is a Cauchy surface. We present three results relevant to this question. First, we deriveExpand
Solutions for gravity coupled to massless gauge fields
An explicit procedure is presented so that from each solution of the coupled Einstein-Maxwell equations for gravity and source-free electromagnetic fields, one can construct a set of solutions of theExpand
Birkhoff theorem for an R+R 2 theory of gravity with torsion
We investigate the gravitational Lagrangian ${L}_{G}=(\frac{{c}^{4}}{16\ensuremath{\pi}G})R\ensuremath{-}(\frac{\ensuremath{\hbar}c}{16\ensuremath{\pi}{\ensuremath{\alpha}}_{G}})Expand
Product yield for ECAE processing
Abstract The fully worked volume and shape of bars processed via equal channel angular extrusion through a 90 die and different multipass routes are reported. Results are given for squareExpand
Non-self-dual gauge fields
Abstract The Ward construction is generalized to non-self-dual gauge fields. Reality and currentless conditions are specified.
Non-self-dual nonlinear gravitons
Penrose has given a twistor description of all self-dual complex Riemannian space-times. We modify his construction to characterize all complex Riemannian space-times and all complex teleparallelExpand
All torsion-free spherical vacuum solutions of the quadratic Poincaré gauge theory of gravity
We find all torsion-free, spherically symmetric, vacuum solutions to the theory of gravity recently proposed by Hehl, Ne'eman, Nitsch, and von der Heyde. There are three classes of solutions: (A) theExpand
The sounds of science—a symphony for many instruments and voices
Sounds of Science is the first movement of a symphony for many (scientific) instruments and voices, united in celebration of the frontiers of science and intended for a general audience. JohnExpand